Apparatus to treat esophageal sphincters

ABSTRACT

A sphincter treatment apparatus has an introducer means including a distal portion means. An expandable device means includes a plurality of arm means. Each arm means of the plurality has a distal section means and a proximal section means. Each of distal sections means of the arm means are coupled and each of the proximal sections means of the arm means are coupled to the introducer means distal portion means. The expandable device means is configured to at least partially dilate a sphincter in a deployed state. An energy delivery device means is introduceable from the introducer means into a selected site of the sphincter. The energy delivery device means is configured to deliver sufficient energy to reduce a frequency of relaxation of the sphincter.

RELATED APPLICATIONS

This application is a divisional of co-pending U.S. patent applicationSer. No. 11/638,952, filed 14 Dec. 2006, which is a divisional ofco-pending U.S. patent application Ser. No. 10/838,292, which is adivisional of U.S. patent application Ser. No. 09/971,085, filed Oct. 4,2001 (now U.S. Pat. No. 6,749,607), which is a continuation of U.S.patent application Ser. No. 09/036,092, filed Mar. 6, 1998, nowabandoned.

FIELD OF THE INVENTION

This invention relates generally to an apparatus to treat sphincters,and more particularly. to an apparatus to treat esophageal sphincters.

DESCRIPTION OF RELATED ART

Gastroesophageal reflux disease (GERD) is a common gastroesophagealdisorder in which the stomach contents are ejected into the loweresophagus due to a dysfunction of the lower esophageal sphincter (LES).These contents are highly acidic and potentially injurious to theesophagus resulting in a number of possible complications of varyingmedical severity. The reported incidence of GERD in the U.S. is as highas 10% of the population (Castell D O; Johnston B T: GastroesophagealReflux Disease: Current Strategies For Patient Management. Arch Fam Med,5 (4):221-7; (1996 April)).

Acute symptoms of GERD include heartburn, pulmonary disorders and chestpain. On a chronic basis, GERD subjects the esophagus to ulcerformation, or esophagitis and may result in more severe complicationsincluding esophageal obstruction, significant blood loss and perforationof the esophagus. Severe esophageal ulcerations occur in 20-30% ofpatients over age 65. Moreover, GERD causes adenocarcinoma, or cancer ofthe esophagus, which is increasing in incidence faster than any othercancer (Reynolds J C: Influence Of Pathophysiology, Severity, And CostOn The Medical Management Of Gastroesophageal Reflux Disease. Am JHealth Syst Pharm, 53 (22 Suppl 3):S5-12 (1996 Nov. 15)).

Current drug therapy for GERD includes histamine receptor blockers whichreduce stomach acid secretion and other drugs which may completely blockstomach acid. However, while pharmacologic agents may provide short termrelief, they do not address the underlying cause of LES dysfunction.

Invasive procedures requiring percutaneous introduction ofinstrumentation into the abdomen exist for the surgical correction ofGERD. One such procedure, Nissen fundoplication, involves constructing anew “valve’ to support the LES by wrapping the gastric fundus around thelower esophagus. Although the operation has a high rate of success, itis an open abdominal procedure with the usual risks of abdominal surgeryincluding: postoperative infection, herniation at the operative site,internal hemorrhage and perforation of the esophagus or of the cardia.In fact, a recent 10 year, 344 patient study reported the morbidity ratefor this procedure to be 17% and mortality 1% (Urschel, J D:Complications Of Antireflux Surgery, Am J Surg 166 (1): 68-70; (1993July)). This rate of complication drives up both the medical cost andconvalescence period for the procedure and may exclude portions ofcertain patient populations (e.g., the elderly and immuno-compromised).

Efforts to perform Nissen fundoplication by less invasive techniqueshave resulted in the development of laparoscopic Nissen fundoplication.Laparoscopic Nissen fundoplication, reported by Dallemagne et al.Surgical Laparoscopy and Endoscopy, Vol. 1, No. 3, (1991), pp. 138-43arid by Hindler et al. Surgical Laparoscopy and Endoscopy, Vol. 2, No.3, (1992), pp. 265-272, involves essentially the same steps as Nissenfundoplication with the exception that surgical manipulation isperformed through a plurality of surgical cannula introduced usingtrocars inserted at various positions in the abdomen.

Another attempt to perform fundoplication by a less invasive techniqueis reported in U.S. Pat. No. 5,088,979. In this procedure, aninvagination device containing a plurality of needles is insertedtransorally into the esophagus with the needles in a retracted position.The needles are extended to engage the esophagus and fold the attachedesophagus beyond the gastroesophageal junction. A remotely operatedstapling device, introduced percutaneously through an operating channelin the stomach wall, is actuated to fasten the invaginatedgastroesophageal junction to the surrounding involuted stomach wall.

Yet another attempt to perform fundoplication by a less invasivetechnique is reported in U.S. Pat. No. 5,676,674. In this procedure,invagination is done by a jaw-like device and fastening of theinvaginated gastroesophageal junction to the fundus of the stomach isdone via a transoral approach using a remotely operated fasteningdevice, eliminating the need for an abdominal incision. However, thisprocedure is still traumatic to the LES and presents the postoperativerisks of gastroesophageal leaks, infection and foreign body reaction,the latter two sequela resulting when foreign materials such as surgicalstaples are implanted in the body.

While the methods reported above are less invasive than an open Nissenfundoplication, some still involve making an incision into the abdomenand hence the increased morbidity and mortality risks and convalescenceperiod associated with abdominal surgery. Others incur the increasedrisk of infection associated with placing foreign materials into thebody. All involve trauma to LES and the risk of leaks developing at thenewly created gastroesophageal junction.

Besides the LES, there are other sphincters in the body which if notfunctionally properly can cause disease states or otherwise adverselyaffect the lifestyle of the patient. Reduced muscle tone or otherwiseaberrant relaxation of sphincters can result in a laxity of tightnessdisease states including, but not limited to, urinary incontinence.

There is a need to provide an apparatus to treat a sphincter and reducea frequency of sphincter relaxation. Another need exists for anapparatus to create controlled cell necrosis in a sphincter tissueunderlying a sphincter mucosal layer. Yet another need exists for anapparatus to create controlled cell necrosis in a sphincter and minimizeinjury to a mucosal layer of the sphincter. There is another need for anapparatus to controllably produce a lesion in a sphincter withoutcreating a permanent impairment of the sphincter's ability to achieve aphysiologically normal state of closure. Still a further need exists foran apparatus to create a tightening of a sphincter without permanentlydamaging anatomical structures near the sphincter. There is stillanother need for an apparatus to create controlled cell necrosis in alower esophageal sphincter to reduce a frequency of reflux of stomachcontents into an esophagus.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide anapparatus that reduces a frequency of sphincter relaxation.

Another object of the invention is to provide an apparatus to createcontrolled cell necrosis in a sphincter tissue underlying a sphinctermucosal layer. Yet another object of the invention is to provide anapparatus to create controlled cell necrosis in a sphincter and minimizeinjury to a mucosal layer of the sphincter.

A further object of the invention is to provide an apparatus tocontrollably produce a lesion in a sphincter without creating apermanent impairment of the sphincter's ability to achieve aphysiologically normal state of closure.

Still another object of the invention is to provide an apparatus tocreate a tightening of a sphincter without permanently damaginganatomical structures near the sphincter.

Another object of the invention is to provide an apparatus to createcontrolled cell necrosis in a lower esophageal sphincter to reduce afrequency of reflux of stomach contents into an esophagus.

These and other objects of the invention are provided in a sphinctertreatment apparatus within an introducer means including a distalportion means. An expandable device means includes a plurality of armmeans. Each arm means has a distal section means and a proximal sectionmeans. Each of the distal section means of the arm means are coupled andeach of the proximal section means Of the arm means are coupled to theintroducer means distal portion means. The expandable device means isconfigured to at least partially dilate a sphincter in a deployed state.An energy delivery device means is introduceable from the introducermeans into a selected site of the sphincter. The energy delivery devicemeans is configured to deliver sufficient energy to reduce a frequencyof relaxation of the sphincter.

In another embodiment, an expandable device means is coupled to anintroducer distal portion means. The expandable device means includes afirst arm means with a proximal and distal section means and a secondarm means with proximal and distal section means. The first and secondarm distal portion means are coupled. The expandable device means isconfigured to at least partially dilate a sphincter in a deployed state.An energy delivery device means is coupled to the expandable devicemeans. The energy delivery device means is configured to deliversufficient energy to reduce a frequency of relaxation of the sphincterwhile minimizing cell necrosis of a mucosal layer of the sphincter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustrated lateral view of the upper GI tract depictingthe position of the sphincter treatment apparatus of the presentinvention in the lower esophageal sphincter.

FIG. 2 is a lateral view of the present invention illustrating theintroducer, expansion device and energy delivery device.

FIG. 3 depicts a lateral view of an embodiment of the invention thatillustrates the use of a sheath to introduce and deploy the expansiondevice.

FIG. 4 illustrates a lateral view of the basket assembly used in anembodiment of the invention.

FIG. 5 is a lateral view of the basket assembly illustrating theplacement of struts on the basket assembly.

FIG. 6A is a lateral view of the junction between the basket arms andthe introducer illustrating a lumen in the basket arm that can be usedfor the advancement of energy delivery devices.

FIG. 6B is a frontal view of a basket arm in an alternative embodimentof the invention illustrating a track in the arm used to advance themovable wire.

FIG. 7A is a cross-sectional view of a section of a basket arm and anenergy delivery device illustrating stepped and tapered sections in thebasket arm apertures and energy delivery device.

FIG. 8A is a lateral view of the basket assembly illustrating the use ofthe advancement member and introducer to position energy deliverydevices into the sphincter wall.

FIG. 8B is a lateral view of the basket assembly illustrating the use ofthe advancement member and basket arms to position energy deliverydevices into the sphincter wall.

FIG. 9 is a cross sectional view illustrating the use of a needleelectrode in combination with an angled aperture segment to select andmaintain a constant penetration angle into the sphincter wall.

FIG. 10 is a lateral view illustrating the placement of needleelectrodes into the sphincter wall by expansion of the basket assembly.

FIG. 11 is a lateral view illustrating the use of an insulation layer onthe needle electrode to protect an area of tissue from RF energy.

FIG. 12 depicts the fluid source and flow path to deliver fluid totreatment site using the introducer.

FIG. 13 is a cross sectional view illustrating a visualization devicecoupled to an embodiment of the invention.

FIG. 14 is an enlarged lateral view illustrating the placement ofsensors on/adjacent the energy delivery device and the coupling ofsensors to a feedback control system.

FIG. 15 is a flow chart illustrating a sphincter treatment method usingthe apparatus of the present invention.

FIG. 16 is a lateral view of sphincter smooth muscle tissue illustratingelectrical foci and electrically conductive pathways for the originationand conduction of aberrant electrical signals in the smooth muscle ofthe lower esophageal sphincter or other tissue.

FIG. 17 is a lateral view of a sphincter wall illustrating theinfiltration of tissue healing cells into a lesion in the smooth tissueof a sphincter following treatment with the sphincter treatmentapparatus of the present invention.

FIG. 18 is a view similar to that of FIG. 17 illustrating shrinkage ofthe lesion site caused by cell infiltration.

FIG. 19 is a lateral view of the esophageal wall illustrating thepreferred placement of lesions in the smooth muscle layer of aesophageal sphincter.

FIGS. 20A-D are lateral views of the sphincter wall illustrating variouspatterns of lesions created by the apparatus of the present invention.

FIG. 21 depicts a block diagram of the feed back control system that canbe used with an embodiment of the invention.

FIG. 22 depicts a block diagram of an analog amplifier, analogmultiplexer and microprocessor used with the feedback control system ofFIG. 21.

FIG. 23 depicts a block diagram of the operations performed in thefeedback control system depicted in FIG. 21.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, one embodiment of a sphincter treatmentapparatus 10 delivers energy to a treatment site 12 to produce lesions14 in a sphincter 16, such as the lower esophageal sphincter (LES). Inthis embodiment, sphincter treatment apparatus 10 comprises a flexibleelongate shaft 18, also called introducer 18, coupled to an expansiondevice 20, in turn coupled with one or more energy delivery devices 22.Introducer 18 has a distal extremity also called introducer end 19.Energy delivery devices 22 are configured to be coupled to a powersource.

Expansion device 20 comprises a plurality of arms 24, with proximal anddistal arms ends 25 and 26. Proximal arm ends 25 are coupled tointroducer end 19. Expansion device 20 has a central longitudinal axis28 and is moveable between contracted and expanded/deployed statessubstantially there along. Expansion device 20 is configured to bepositionable in a sphincter 16 (such as the LES) or adjacent anatomicalstructure (such as the cardia of the stomach) and is further configuredto partially dilate sphincter 16 when in the deployed state. Energydelivery devices 22 are configured to be introduceable from introducer18 and to contact and/or penetrate a targeted treatment site 12 in asphincter wall 30 or adjoining anatomical structure. They are furtherconfigured to deliver energy to treatment site 12.

Referring now to FIG. 2, introducer 18 is configured to be coupled toexpansion device 20 and has sufficient length to position expansiondevice 20 in the LES and/or stomach using a transoral approach. Typicallengths for introducer 18 include a range of 40-180 cm. Introducer 18may be circular or oval in cross section. Also, introducer 18 may beflexible, articulated, coil-reinforced, or steerable, or any combinationthereof. Suitable materials for introducer 18 include polyethylenes,polyurethanes, silicones and other biocompatible polymers known to thoseskilled in the art.

Introducer 18 may also be coated with a lubricious coating as is wellknown to those skilled in the art. Introducer 18 may have one or morelumens 32, that extend the full length of introducer 18, or only aportion thereof. Lumens 32 may be used as paths for the delivery offluids and gases, as well as providing channels for cables, catheters,guide wires, pull wires, insulated wires, and optical fibers.

In another embodiment of the invention depicted in FIGS. 3A and 3B, anintroduction member 34, also called a sheath 34, is used to introducesphincter treatment apparatus 10 into the LES. Sheath 34 can alsofunction as a sheath for expansion device 20 to keep it in a nondeployedor contracted state during introduction into the LES. To facilitate thisfunction, sheath 34 contains a sheath lumen 36 of sufficient innerdiameter to allow free movement of sphincter treatment apparatus 10within sheath lumen 36. Sheath 34, sheath lumen 36 and sphinctertreatment apparatus 10 are configured to allow expansion device 20 to gofrom a contracted state to an expanded state and vice versa by either i)the retraction or advancement of sheath 34, or ii) the advancement orwithdrawal of sphincter treatment apparatus 10. Sheath 34 may beflexible, articulated, coil-reinforced or steerable, or any combinationthereof Suitable materials for sheath 34 include polyethylenes,polyurethanes, silicones, polytetrafluoroethylenes and otherbiocompatible polymers known to those skilled in the art. Typicaldiameters for sheath lumen 36 include 0.1 to 2 inches, while typicallengths include 40-180 cms.

Referring now to FIG. 4, in another embodiment of the present invention,expansion device 20 comprises one or more elongated arms 24 that arejoined at their proximal ends 25 and distal ends 26 to form a basketassembly 38. Proximal arm end 25 is attached to a supporting structure,which can be distal end 19 of introducer 18 or a proximal cap 40.Likewise, distal arm end 26 is also attached to a supporting structurewhich can be a distal basket cap 42 or introducer 18. Arms 24 are of asufficient number, two or more, to sufficiently open and efface thefolds of sphincter 16 to allow treatment with sphincter treatmentapparatus 10, while preventing herniation of sphincter wall 30 into thespaces 44 between arms 24.

Arms 24 may form a variety of geometric shapes including, curved,rectangular, trapezoidal, triangular, or any combination thereof Also,arms 24 can have an outwardly bowed shaped memory for expanding basketassembly 38 into engagement with sphincter wall 30. Arms 24 may bepreshaped at time of manufacture or shaped by the physician. Arms 24 canhave a variety of cross sectional geometries including, circular,rectangular and crescent-shaped. The circumferential spacing of arms 24can be symmetrical or asymmetrical with respect to a circumferencearound longitudinal axis 28. Suitable materials for arms 24 includespring steel, stainless steel, superelastic shape memory metals such asnitinol, or stiff shaft plastic tubing as is well known to those skilledin the art. Arms 24 may also be color-coded to facilitate theiridentification via visual medical imaging methods and equipment, such asendoscopic methods, which are well known to those skilled in the art.

In another embodiment of the invention depicted in FIG. 5, a supportingmember 46 is attached to two or more arms 24. Supporting member 46, alsocalled strut 46, can be attached to arms 24 along a circumference ofbasket assembly 38. Strut 46 may also contain apertures 50 in one ormore places that extend through strut 46 to arm 24 as will be discussedherein. The cross sectional geometry of strut 46 can be rectangular,circular or crescent-shaped. Suitable materials for strut 46 includespring steel, stainless steel, superelastic shape memory metals such asnitinol, or stiff shaft plastic tubing as is well known to those skilledin the art.

Referring now to FIG. 6A, arms 24 may be solid or hollow with acontinuous arm lumen 48 that may be coupled with introducer lumens 32.Also arms 24 may have one or more apertures 50 that may coupled to armlumen 48. Coupled lumens 32 and 48, and apertures 50 provide a path forthe delivery of a fluid or energy delivery device 22 from introducer 18to the surface or interior of sphincter wall 30. As shown in FIG. 6B,arms 24 may also have a partially open channel 52, also called a track52, that functions as a guide track for the travel of an advancementmember (discussed herein) and/or energy delivery device 22 that permitthe controlled placement of energy delivery devices 22 at or intosphincter wall 30. Referring now to FIG. 7, apertures 50 may havetapered sections 54 and/or stepped sections 56 in all or part of theirlength, that are used to control the penetration depth of energydelivery devices 22 into sphincter wall 30 as will be discussed herein.Energy delivery devices 22 may have similar tapered sections 54′ and/orstepped sections 56′.

Referring now to FIGS. 8A and 8B, in another embodiment of theinvention, energy delivery devices 22 can be coupled to an energy devicedelivery member 57, also called an advancement member 57. Advancementmember 57 can be an insulated wire, an insulated guide wire, aplastic-coated stainless steel hypotube with internal wiring or aplastic catheter with internal wiring as is well known to those skilledin the art. Advancement member 57 is configured to be able to introduceenergy delivery device 22 into sphincter wall 30 via introducer (seeFIG. 8A) or basket assembly 38 as will be discussed herein (see FIG.8B). Advancement member 57 is of sufficient length to position energydelivery device 22 in the LES and/or stomach using a transoral approach.Typical lengths for advancement member 57 include a range of 40-180 cms.

In another embodiment of the invention depicted in FIG. 9, energydelivery device 22 has a distal portion 58 that is configured topenetrate sphincter wall 30 with a minimum amount of tearing of themucosal and submucosal layers 60 and 62 of sphincter 16. This isfacilitated by maintaining a constant angle of penetration 64, alsocalled penetration angle 64, of distal portion 58 into sphincter wall 30during the time that energy delivery device 22 is advanced intosphincter wall 30. The typical range for penetration angle 64 liesbetween 1 and 90°. This can be accomplished through the use of a needle58′ for distal energy delivery device portion 58, coupled with an angledaperture segment 50′ having a preselected penetration angle 64. Needle58′ is of sufficient sharpness and length to penetrate into the smoothmuscle of sphincter wall 30. In a further embodiment, needle 58′ can bea needle electrode 58. Distal portion 58, including needle 58′ andneedle electrode 58 can also be stepped or tapered to enable control ofenergy delivery device (see FIG. 7). Suitable materials for needle 58′and needle electrodes 58″ include 304 stainless steel and other metalsknown to those skilled in the art.

In another embodiment of the invention, energy delivery device 22 iscoupled to arm 24. As shown in FIG. 10, this can be accomplished byattaching needle 58′ to arm 24. When sphincter treatment apparatus 10 isproperly positioned at the treatment site 12, needles 58′ are deployedby expansion of basket assembly 38, resulting in the protrusion ofneedle 58′ into the smooth muscle tissue of sphincter wall 30 (see FIG.10). Referring back to FIG. 9, coupling can also be accomplished byemploying arm 24 to introduce energy delivery device 22 into sphincterwall 30 via use of arm lumen 48.

Turning now to a discussion of energy delivery, suitable power sourcesand energy delivery devices 22 that can be employed in one or moreembodiments of the invention include or more of the following: (i) aradio-frequency (RF) source coupled to an RF electrode, (ii) a coherentsource of light coupled to an optical fiber, (iii) an incoherent lightsource coupled to an optical fiber, (iv) a heated fluid coupled to acatheter with a closed channel configured to receive the heated fluid,(v) a heated fluid coupled to a catheter with an open channel configuredto receive the heated fluid, (vi) a cooled fluid coupled to a catheterwith a closed channel configured to receive the cooled fluid, (vii) acooled fluid coupled to a catheter with an open channel configured toreceive the cooled fluid, (viii) a cryogenic fluid, (ix) a resistiveheating source, (x) a microwave source providing energy from 915 MHz to2.45 GHz and coupled to a microwave antenna, or (xi) an ultrasound powersource coupled to an ultrasound emitter, wherein the ultrasound powersource produces energy in the range of 300 KHZ to 3 GHz. For ease ofdiscussion for the remainder of this application, the power sourceutilized is an RF source and energy delivery device 22 is one or more RFelectrodes 66, also described as electrodes 66. However, all of theother herein mentioned power sources and energy delivery devices areequally applicable to sphincter treatment apparatus 10.

For the case of RF energy, RF electrode 66 may be operated in eitherbipolar or monopolar mode with a ground pad electrode. In a monopolarmode of delivering RF energy, a single electrode 66 is used incombination with an indifferent electrode patch that is applied to thebody to form the other electrical contact and complete an electricalcircuit. Bipolar operation is possible when two or more electrodes 66are used. Multiple electrodes 66 may be used. These electrodes may becooled as described herein. Electrodes 66 can be attached to advancementmember 57 by the use of soldering methods which are well known to thoseskilled in the art.

Referring now to FIG. 11, RF electrodes 66 can have an insulating layer68, covering an insulated segment 70 except for an exposed segment 72.For purposes of this disclosure, an insulator or insulation layer is abarrier to either thermal or electromagnetic energy flow including RFenergy flow. Insulated segment 70 is of sufficient length to extend intosphincter wall 30 and minimize the transmission of RF energy to aprotected site 74 near or adjacent to insulated segment 70. Typicallengths for insulated segment 70 include, but are not limited to, 1-4mm. Suitable materials for insulating layer 68 include electricallyinsulating plastics and other materials well known to those skilled inthe art.

In another embodiment of the invention, the depth of penetration ofenergy delivery device 22 into sphincter wall 30 is controllable. Thiscan be accomplished by the selection and control of the. dimensionalrelationships (e.g. the amount of clearance between inner and outerdiameters) of energy delivery devices 22 and/or advancement member 57 toone or more of the following elements: arm lumen 48, apertures 50 andtrack 52. Control of penetration depth can also be accomplished throughthe use of tapered and/or stepped sections in one or more of thepreceding elements as is discussed herein. In another embodiment,penetration depth control can be accomplished by the use of one or moreof a variety of positional control means, known to those skilled in theart, that are coupled to sphincter treatment apparatus 10. Suchpositional control means include stepper motor systems, indexingmechanisms and micromanipulators.

Referring now to FIG. 12, in another embodiment of the invention, fluidcan be delivered to treatment site 12 via introducer 18. This isaccomplished by the coupling of introducer 18 to a fluid source 76 viaintroducer lumen 32.

Referring now to FIG. 13, another embodiment of sphincter treatmentapparatus 10 includes a visualization device 78 coupled to introducer18. Visualization device 78 can include a combination of one or more ofthe following: a viewing scope, an expanded eyepiece, fiber optics (bothimaging and illuminating fibers), video imaging devices and the like.

As shown in FIG. 14, one or more sensors 80 may be positioned adjacentto or on electrode 66 for sensing the physical properties of sphinctertissue at treatment site 12. Sensors 80 permit accurate determination ofthe physical properties of sphincter wall 30 at an electrode-tissueinterface 82. Such physical properties include temperature, electricalconductivity, electrical capacitance, thermal conductivity, density,thickness, strength, elasticity, moisture content, optical reflectance,optical transmittance, optical absorption acoustical impedance andacoustical absorption. Sensors 80 can be positioned at any position onexpansion device 20, electrode 66 or basket assembly 38. Suitablesensors that may be used for sensor 80 include: thermocouples, fiberoptics, photomultipliers, resistive wires, thermocouple IR detectors,thin film sensors, anemometric sensors and ultrasound sensors. Sensor 80can be coupled to a feedback control system 84, described herein. Thecoupling of sensor 80 to feedback control system 84 can be used toregulate the delivery of energy, fluids and gases to one or more of thefollowing locations: treatment site 12, sphincter wall 30, and electrodetissue interface 82.

FIG. 15 is a flow chart illustrating a method for using sphinctertreatment apparatus 10. First, sphincter treatment apparatus 10 isintroduced into the esophagus under local anesthesia and positioned attreatment site 12. Sphincter treatment apparatus 10 can be introducedinto the esophagus by itself or through a lumen in an endoscope (notshown), such as disclosed in U.S. Pat. Nos. 5,448,990 and 5,275,608,incorporated herein by reference, or a similar esophageal access deviceknown to those skilled in the art. Basket assembly 38 is expanded asdescribed herein. This serves to temporarily dilate the LES sufficientlyto efface all or a portion of the folds of the LES. In an alternativeembodiment, esophageal dilation and subsequent LES fold effacement canbe accomplished by insufflation of the esophagus (a known technique)using gas introduced into the esophagus through introducer lumen 32, anendoscope, or others esophageal access devices known to those skilled inthe art. Once treatment is completed, basket assembly 38 is returned toits predeployed or contracted state and sphincter treatment apparatus 10is withdrawn from the esophagus. This results in the LES returning toapproximately its pretreatment state and diameter. It will beappreciated that the above procedure is applicable in whole or part tothe treatment of other sphincters in the body.

The diagnostic phase of the procedure then begins and can be performedusing a variety of diagnostic methods known to those skilled in the artincluding the following: (i) visualization of the interior surface ofthe esophagus via an endoscope or other viewing apparatus inserted intothe esophagus, (ii) visualization of the interior morphology of theesophageal wall using ultrasonography to establish a baseline for thetissue to be treated, (iii) impedance measurement to determine theelectrical conductivity between esophageal mucosal and submucosal layers60 and 62 and sphincter treatment apparatus 10, and (iv) measurement andsurface mapping of electropotential signals of the LES and surroundinganatomical structures during varying time intervals which may includesuch events as depolarization, contraction and repolarization ofgastroesophageal smooth muscle tissue. This latter technique is done todetermine target treatment sites 12 in the LES or adjoining anatomicalstructures that are acting as electrical foci 107 or electricallyconductive pathways 109 for abnormal or inappropriate polarization andrelaxation of the smooth muscle of the LES (Refer to FIG. 16).

After diagnosis, the treatment phase of the procedure begins. In thisphase of the procedure, the delivery of energy to treatment site 12 canbe conducted under feedback control, manually or by a combination ofboth. Feedback control (described herein) enables sphincter treatmentapparatus 10 to be positioned and retained in the esophagus duringtreatment with minimal attention by the physician. Electrodes 66 can bemultiplexed in order to treat the entire targeted treatment site 12 oronly a portion thereof. Feedback can be included and is achieved by theuse of one or more of the following methods: (i) visualization, (ii)impedance measurement, (iii) ultrasonography, (iv) temperaturemeasurement; and, (v) contractile force measurement via manometry. Thefeedback mechanism permits the selected on-off switching of differentelectrodes 66 in a desired pattern, which can be sequential from oneelectrode 66 to an adjacent electrode 66, or can jump around betweennon-adjacent electrodes 66. Individual electrodes 66 are multiplexed andvolumetrically controlled by a controller.

The area and magnitude of cell injury in the LES or sphincter 16 canvary. However, it is desirable to deliver sufficient energy to thetargeted treatment site 12 to be able to achieve tissue temperatures inthe range of 55-95° C. and produce lesions 14 at depths ranging from 1-4mms from the interior surface of the LES or sphincter wall 30. Typicalenergies delivered to the esophageal or stomach wall include, but arenot limited to, a range between 100 and 50,000 joules per electrode 66.It is also desirable to deliver sufficient energy such that resultinglesions 14 have a sufficient magnitude and area of cell injury to causean infiltration of lesion 14 by fibroblasts 110, myofibroblasts 112,macrophages 114 and other cells involved in the tissue healing process(refer to FIG. 17). As shown in FIG. 18, these cells cause a contractionof tissue around lesion 14, decreasing its volume and/or altering thebiomechanical properties at lesion 14 so as to result in a tightening ofthe LES or sphincter 16. These changes are reflected in transformedlesion 14′. The diameter of lesions 14 can vary between 0.1 to 4 mm. Itis preferable that lesions 14 are less than 4 mmns in less than 4 mms indiameter in order to reduce the risk of thermal damage to mucosal andsubmucosal layers 60 and 62. In one embodiment, a 2 mm diameter lesion14 centered in the wall of the smooth muscle provides a 1 mm buffer zoneon either side of lesion 14 to prevent damage to mucosal and submucosallayers 60 and 62 and the adventitia (not shown), while still allowingfor cell infiltration and subsequent sphincter tightening onapproximately 50% of the thickness of the wall of the smooth muscle(refer to FIG. 19).

It is desirable that lesions 14 are predominantly located in the smoothmuscle layer of selected sphincter 16 at the depths ranging from 1 to 4mm from the interior surface of sphincter wall 30. However, lesions 14can vary both in number and position within sphincter wall 30. It may bedesirable to produce a pattern of multiple lesions 14 within thesphincter smooth muscle tissue in order to obtain a selected degree oftightening of the LES or other sphincter 16. Typical lesion patternsshown in FIGS. 20 A-D include, but are not limited to, (i) a concentriccircle of lesions 14 all at fixed depth in the smooth muscle layerevenly spaced along the radial axis of sphincter 16, (ii) a wavy orfolded circle of lesions 14 at varying depths in the smooth muscle layerevenly spaced along the radial axis of sphincter 16, (iii) lesions 14randomly distributed at varying depths in the smooth muscle, but evenlyspaced in a radial direction and, (iv) an eccentric pattern of lesions14 in one or more radial locations in the smooth muscle wall.Accordingly, the depth of RF and thermal energy penetration intosphincter 16 is controlled and selectable. The selective application ofenergy to sphincter 16 may be the even delivery of RF energy to theentire targeted treatment site 12, a portion of it, or applyingdifferent amounts of RF energy to different sites depending on thecondition of sphincter 16. If desired, the area of cell injury can besubstantially the same for every treatment event.

A second diagnostic phase may be included after the treatment iscompleted. This provides an indication of LES tightening treatmentsuccess, and whether or not a second phase of treatment, to all or onlya portion of the esophagus, now or at some later time, should beconducted. The second diagnostic phase is accomplished through one ormore of the following methods: (i) visualization, (ii) measuringimpedance, (iii) ultrasonography, (iv) temperature measurement, or (v)measurement of LES tension and contractile force via manometry.

In one embodiment of the invention, sensor 80 is coupled to an open orclosed loop feedback control system 84. Referring now to FIG. 21, anopen or closed loop feedback system 84 couples sensor 80, now describedas sensor 346, to an energy source 392. In this embodiment, an energydelivery device 314 is one or more RF electrodes 314; however, invarious other embodiments, energy delivery device 314 may include othersdescribed herein. Similarly, in this embodiment, sensor 346 sensestemperature, but in various other embodiments, sensor 346 may senseother physical properties described herein.

The temperature of the tissue, or of RF electrode 314, is monitored, andthe output power of energy source 392 adjusted accordingly. Thephysician can, if desired, override the closed or open loop system 84. Amicroprocessor 394 can be included and incorporated in the closed oropen loop system to switch power on and off, as well as modulate thepower. The closed loop system 84 utilizes microprocessor 394 to serve asa controller, monitor the temperature, adjust the RF power, analyze theresult, refeed the result, and then modulate the power.

With the use of sensor 346 and feedback control system 84, tissueadjacent to RF electrode 314 can be maintained at a desired temperaturefor a selected period of time without causing a shut down of the powercircuit to electrode 314 due to the development of excessive electricalimpedance at electrode 314 or adjacent tissue. Each RF electrode 314 isconnected to resources which generate an independent output. The outputmaintains a selected energy at RF electrode 314 for a selected length oftime.

Current delivered through RF electrode 314 is measured by current sensor396. Voltage is measured by voltage sensor 398. Impedance and power arethen calculated at power and impedance calculation device 400. Thesevalues can then be displayed at user interface and display 402. Signalsrepresentative of power and impedance values are received by acontroller 404.

A control signal is generated by controller 404 that is proportional tothe difference between an actual measured value, and a desired value.The control signal is used by power circuits 406 to adjust the poweroutput an appropriate amount in order to maintain the desired powerdelivered at respective RF electrodes 314.

In a similar manner, temperatures detected at sensor 346 providefeedback for maintaining a selected power. Temperature at sensor 346 isused as a safety means to interrupt the delivery of power when maximumpre-set temperatures are exceeded. The actual temperatures are measuredat temperature measurement device 408, and the temperatures aredisplayed at user interface and display 402. A control signal isgenerated by controller 404 that is proportional to the differencebetween an actual measured temperature and a desired temperature. Thecontrol signal is used by power circuits 406 to adjust the power outputan appropriate amount in order to maintain the desired temperaturedelivered at the sensor 346. A multiplexer can be included to measurecurrent, voltage and temperature, at the sensor 346, and energy can bedelivered to RF electrode 314 in monopolar or bipolar fashion.

Controller 404 can be a digital or analog controller, or a computer withsoftware. When controller 404 is a computer it can include a CPU coupledthrough a system bus. This system can include a keyboard, a disk drive,or other non-volatile memory systems, a display, and other peripherals,as are known in the art. Also coupled to the bus is a program memory anda data memory.

User interface and display 402 includes operator controls and a display.Controller 404 can be coupled to imaging systems including, but notlimited to, ultrasound, CT scanners, X-ray, MRI, mammographic X-ray andthe like. Further, direct visualization and tactile imaging can beutilized.

The output of current sensor 396 and voltage sensor 398 are used bycontroller 404 to maintain a selected power level at RF electrode 314.The amount of RF energy delivered controls the amount of power. Aprofile of the power delivered to electrode 314 can be incorporated incontroller 404 and a preset amount of energy to be delivered may also beprofiled.

Circuitry, software and feedback to controller 404 result in processcontrol, the maintenance of the selected power setting which isindependent of changes in voltage or current, and is used to change thefollowing process variables: (i) the selected power setting, (ii) theduty cycle (e.g., on-off time), (iii) bipolar or monopolar energydelivery; and, (iv) fluid delivery, including flow rate and pressure.These process variables are controlled and varied, while maintaining thedesired delivery of power independent of changes in voltage or current,based on temperatures monitored at sensor 346.

Referring now to FIG. 22, current sensor 396 and voltage sensor 398 areconnected to the input of an analog amplifier 410. Analog amplifier 410can be a conventional differential amplifier circuit for use with sensor346. The output of analog amplifier 410 is sequentially connected by ananalog multiplexer 412 to the input of A/D converter 414. The output ofanalog amplifier 410 is a voltage which represents the respective sensedtemperatures. Digitized amplifier output voltages are supplied by A/Dconverter 414 to microprocessor 394. Microprocessor 394 may be a type68HCII available from Motorola. However, it will be appreciated that anysuitable microprocessor or general purpose digital or analog computercan be used to calculate impedance or temperature.

Microprocessor 394 sequentially receives and stores digitalrepresentations of impedance and temperature. Each digital valuereceived by microprocessor 394 corresponds to different temperatures andimpedances.

Calculated power and impedance values can be indicated on user interfaceand display 402. Alternatively, or in addition to the numericalindication of power or impedance, calculated impedance and power valuescan be compared by microprocessor 394 to power and impedance limits.When the values exceed predetermined power or impedance values, awarning can be given on user interface and display 402, andadditionally, the delivery of RF energy can be reduced, modified orinterrupted. A control signal from microprocessor 394 can modify thepower level supplied by energy source 392.

FIG. 23 illustrates a block diagram of a temperature and impedancefeedback system that can be used to control the delivery of energy totissue site 416 by energy source 392 and the delivery of a coolingmedium to electrode 314 and/or tissue site 416 by flow regulator 418.Energy is delivered to RF electrode 314 by energy source 392, andapplied to tissue site 416. A monitor 420 ascertains tissue impedance,based on the energy delivered to tissue, and compares the measuredimpedance value to a set value. If measured impedance is withinacceptable limits, energy continues to be applied to the tissue. Howeverif the measured impedance exceeds the set value, a disabling signal 422is transmitted to energy source 392, ceasing further delivery of energyto RF electrode 314.

The control of the delivery of cooling medium to electrode 314 and/ortissue site 416 is done in the following manner. During the applicationof energy, temperature measurement device 408 measures the temperatureof tissue site 416 and/or RF electrode 314. A comparator 424 receives asignal representative of the measured temperature and compares thisvalue to a pre-set signal representative of the desired temperature. Ifthe measured temperature has not exceeded the desired temperature,comparator 424 sends a signal to flow regulator 418 to maintain thecooling solution flow rate at its existing level. However if the tissuetemperature is too high, comparator 424 sends a signal to a flowregulator 418 (connected to an electronically controlled micropump, notshown) representing a need for an increased cooling solution flow rate.

The foregoing description of a preferred embodiment of the invention hasbeen presented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formsdisclosed. Obviously, many modifications and variations will be apparentto practitioners skilled in this art. It is intended that the scope ofthe invention be defined by the following claims and their equivalents.

1. A sphincter treatment apparatus comprising: an introducer having anintroducer lumen, an expandable device coupled to the introducer, theexpandable device including a first arm with a proximal section and adistal section and a second arm with a proximal section and a distalsection, the first and second arm distal sections being coupled, atleast one of the first and second arms including an arm lumen coupled influid communication with the introducer lumen for delivery of a fluid,the expandable device being configured to at least partially dilate asphincter in a deployed state, and an energy delivery device coupled tothe expandable device.
 2. An apparatus as in claim 1 wherein at least aportion of the energy delivery device is advanceable into the sphincter.3. An apparatus as in claim 1 wherein the at least one of the first andsecond arms includes an aperture coupled to the introducer lumen andadapted to provide a path for delivery of the fluid from the introducer.4. An apparatus as in claim 3 wherein the fluid is cooling fluid.
 5. Amethod of treating a sphincter comprising: providing an introducer, theintroducer carrying an expandable device, providing an energy deliverydevice coupled to the expandable device, deploying the introducer to atargeted tissue site at or near a sphincter, expanding the expandabledevice to at least partially dilate the sphincter, delivering energyfrom the energy delivery device to the targeted tissue site, anddelivering a cooling fluid from the introducer.
 6. A method as in claim5 wherein the expandable device includes a first arm with a proximalsection and a distal section and a second arm with a proximal sectionand a distal section, the first and second arm distal sections beingcoupled.
 7. A method as in claim 6 wherein at least one of the first andsecond arms includes a lumen.
 8. A method as in claim 5 wherein theintroducer includes a lumen.
 9. A method as in claim 5 wherein thecooling fluid is delivered at a sensed flow rate, further comprising,measuring the temperature of at least one of the tissue site and theenergy delivery device, and comparing the measured temperature to apre-set desired temperature.
 10. A method as in claim 9, furthercomprising maintaining the flow rate if the measured temperature doesnot exceed the desired temperature.
 11. A method as in claim 9, furthercomprising increasing the flow rate if the measured temperature exceedsthe desired temperature.